Acetals of lactams and acid amides. 60. Novel approach to the synthesis of γ-carbolines

N-Alkylation of 2-methyl-5-nitroindole followed by the Vilsmeyer reaction has given some 2-methyl-3-formyl-5-nitro-N-alkylindoles, which on reaction with DMF diethyl acetal afford 2-(-dimethylamino)vinylindoles. Heating the latter with ammonia provided a novel synthesis of -carbolines. Condensation of 1,2-dimethyl-3-formyl-5-nitroindole with dimethylacetamide diethyl acetal gave 2-dimethylamino-6-nitro-9-methylcarbazole.For Communication 59, see 1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1483–1486, November, 1990.